EP1617283A1 - Motor driving apparatus, digital camera, and motor controlling method - Google Patents
Motor driving apparatus, digital camera, and motor controlling method Download PDFInfo
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- EP1617283A1 EP1617283A1 EP05251119A EP05251119A EP1617283A1 EP 1617283 A1 EP1617283 A1 EP 1617283A1 EP 05251119 A EP05251119 A EP 05251119A EP 05251119 A EP05251119 A EP 05251119A EP 1617283 A1 EP1617283 A1 EP 1617283A1
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- EP
- European Patent Office
- Prior art keywords
- motor
- driving apparatus
- resistance
- output voltage
- voltage
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- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
- G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
- G03B7/08—Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
- G03B7/081—Analogue circuits
- G03B7/085—Analogue circuits for control of aperture
Definitions
- the present invention relates to energization of a motor, and more specifically, to a motor driving apparatus that controls a power source of a lens barrel motor of a digital camera, a digital camera, and a motor controlling method.
- a lens barrel in cameras such as a digital camera
- a method for high-speed activation a high voltage is applied at a time of activation of a motor.
- supply voltage is directly used when a motor is driven at a high speed, and the voltage is lowered during the motor is driven at an ordinary speed to reduce an electric current for the motor.
- a motor driving apparatus includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor.
- the power circuit varies resistance of the feedback variable resistance at a time of start of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- a motor driving apparatus includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor.
- the power circuit varies resistance of the feedback variable resistance at a time of termination of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- a motor driving apparatus includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor.
- the power circuit varies resistance of the feedback variable resistance at times of start and termination of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- a digital camera includes the motor driving apparatus according to the above aspects of the present invention.
- a motor controlling method includes controlling, via a feedback variable resistance, an output voltage that is applied to a motor.
- the controlling includes varying resistance of the feedback variable resistance at a time of at least one of start of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- Fig. 4 is a block diagram of a battery terminal voltage measuring unit according to a first embodiment of the present invention.
- the battery terminal voltage measuring unit includes a power source unit 703, 701, and 702, a power switch 1-22, an input smoothing capacitor 1-11, a voltage step up coil 1-12, a rectifier diode 1-13, an output smoothing capacitor 1-15, a load 1-21 (corresponding to 204, 207, 205, 209, 206, 208, 210 and 211 shown in Fig. 1), a feedback resistance 1 1-16, a feedback resistance 2 1-17, a feedback resistance 3 1-18, a feedback resistance short transistor 1-19, and a direct circuit (DC)-DC converter integrated circuit (IC) 1-2.
- DC direct circuit
- IC direct circuit
- the DC-DC converter IC 1-2 includes an IC power source 1-3, an output drive circuit 1 1-4, a pulse width modulation (PWM) comparator 1-8, a sawtooth wave generating circuit 1-7, an error amplifier (AMP) 1-9, an internal power source 1-10, and a short/overvoltage protection circuit 1-23.
- PWM pulse width modulation
- AMP error amplifier
- This signal and sawtooth wave levels are compared with each other by the PWM comparator 1-8 and pulse outputs are output.
- the pulse outputs are output through the output drive circuit 1-4.
- the short/overvoltage protection circuit 1-23 turns off the DC-DC converter IC when an output voltage exceeds a certain range.
- An electric charge stored in the voltage step up coil 1-12 by switching # operation of the MOS 1-20 is rectified by the rectifier diode 1-13 and supplied to the load 1-21 smoothened by the output smoothing capacitor 1-15.
- the MOS 1-20 turns off by a reverse operation of the above operation.
- Fig. 5 is a block diagram of a battery terminal voltage measuring unit according to a second embodiment of the present invention in which synchronized rectification is added.
- the battery terminal voltage measuring unit according to the second embodiment includes the power source unit 703, 701, and 702, the power switch 1-22, the input smoothing capacitor 1-11, the voltage step up coil 1-12, the rectifier diode 1-13, a synchronized rectification MOS 1-14, the output smoothing capacitor 1-15, the load 1-21 (corresponding to 204, 207, 205, 209, 206, 208, 210, and 211 shown in Fig. 1), the feedback resistance 1 1-16, the feedback resistance 2 1-17, the feedback resistance 3 1-18, the feedback resistance short transistor 1-19, and the DC-DC converter IC 1-2.
- the DC-DC converter IC 1-2 includes the IC power source 1-3, the output drive circuit 1 1-4, an inverting circuit 1-5, an output drive circuit 2 1-6, the PWM comparator 1-8, the sawtooth wave generating circuit 1-7, the error AMP 1-9, the internal power source 1-10, and the short/overvoltage protection circuit 1-23.
- This signal and sawtooth wave levels are compared with each other by the PWM comparator 1-8 and pulse outputs are output.
- the pulse outputs are output through the output drive circuit 1-4, the inverting circuit 1-5, and the output drive circuit 1-6.
- An electric charge stored in the voltage step up coil 1-12 by switching # operation of the MOS 1-20 is rectified by the rectifier diode 1-13 and supplied to the load 1-21 smoothened by the output smoothing capacitor 1-15.
- the MOS 1-14 turns on while the diode carries out the rectifying action and is a switch for synchronized rectification that supplements Vf of the diode.
- Both metal oxide semiconductors (MOSs) 1-14 and 1-20 may be substituted with transistors. Further, the transistor may be substituted with the MOS.
- Fig. 1 is a block diagram of a digital camera according to an embodiment of the present invention.
- the digital camera includes a lens system 2, a focus lens system 201, a zoom lens system 202, a mechanism 203 including diaphragm and the like, a focus motor 204, a zoom motor 205, a diaphragm motor 206, a focus motor driving apparatus 207, a zoom motor driving apparatus 208, a diaphragm motor driving apparatus 209 (a shutter motor 210 and a shutter motor driving apparatus 211 are separately illustrated in this example), a timing generator (TG) 301, a charge coupled device (CCD) 302, a correlation double sampling (CDS) circuit 303, an automatic gain control amplifier (AGC amplifier) 304, an analog-to-digital (A/D) converter 305, an image pre-processor (IPP) 306, a discrete cosine transform (DCT) 308, a Huffman encoder/decoder 309, a memory card controller (MCC)
- the lens unit includes the mechanism 203 including the lens system 2, a diaphragm, a filter, and the like.
- a mechanical shutter of the mechanism 203 exposes two fields.
- a shutter mechanism is separately illustrated as an exposing unit, the mechanism 203 may also serve as the shutter mechanism.
- the lens system 2 is formed of, for example, a varifocal lens and is constructed from the focal lens system 201 and the zoom lens system 202.
- the focus motor driving apparatus 207 drives the focus motor 204 according to control signals supplied by the controller 4 to move the focal lens system 201 to the optical axis direction.
- the zoom motor driving apparatus 208 drives the zoom motor 205 according to the control signals supplied by the controller 4 to move the zoom lens system 202 to the optical axis direction.
- the diaphragm motor driving apparatus 209 drives the mechanism 203 according to the control signals supplied by the controller 4 to set, for example, a diaphragm stop of the diaphragm.
- the CCD 302 converts an image input via the lens unit into electric signals (analog image data).
- the CDS circuit 303 is a circuit to make noise reduced for a CCD-type image pickup device.
- the AGC amplifier 304 corrects the level of the signals that have been subjected to correlation double sampling in the CDS circuit 303.
- the setting is done by setting the setting data (control voltage) on the AGC amplifier 304 via the D/A converter built in the AGC amplifier 304.
- the A/D converter 305 converts the analog image data input from the CCD via the AGC amplifier 304 into digital image data.
- the output signals from the CCD 302 are converted into digital signals via the CDS circuit 303 and the AGC amplifier 304, and by the A/D converter 305 at an optimum sampling frequency, for example, at integral multiple of sub-carrier frequencies of national television system committee (NTSC) signals).
- NTSC national television system committee
- the image pre-processor (IPP) 306, the discrete cosine transform (DCT) 308, and the Huffman encoder/decoder 309 that serve as a digital signal processing unit separate the digital image data input from the A/D converter 305 into color difference (Cb and Cr) and luminance (Y), and carry out various processing and data processing to correct and compress/extend an image.
- the DCT 308 and the Huffman encoder/decoder 309 carry out, for example, orthogonal transformation/reverse orthogonal transformation that is one step of image compression/extension compliant with the Joint Photographic Experts Group (JPEG), Huffman coding/decoding that is one step of the image compression/extension compliant with the JPEG, and so forth.
- JPEG Joint Photographic Experts Group
- the IPP 306 detects luminance data (Y) of image data G, and outputs an autoexposure (AE) evaluation value corresponding to the detected luminance data (Y) to the controller 4.
- This AE evaluation value represents luminance (brightness) of the subject.
- the IPP 306 outputs auto white balance (AWB) evaluation values corresponding to each luminance data (Y) of red (R), green (G) and blue (B) image data, respectively, to the controller 4 within a preset color temperature range.
- AWB evaluation values represent color elements of the subject.
- the memory card controller (MCC) 310 stores the compression-processed image once and records it to the PC card 312 or reads it out of the PC card 312 via the card interface 311.
- the numeral 313 represents a driver for external communication and is used for communication with external units according to standard communication protocols such as universal serial bus (USB) and Institute of Electrical and Electronics Engineers (IEEE) 1394, and connected to a personal computer (PC) 001 and the like, to swap data with them.
- the driver for external communication 313 is made capable of connecting to the PC 001 or the AC adapter 703 via a communication/power source adapter connectable to a camera, thereby allowing power and communication to be swapped.
- the LCD displaying unit 602 is formed of a transmission-type LCD and displays image data, an operation menu, and the like.
- the auxiliary lamp 603 is a back light to illuminate the LCD displaying unit 602 and is formed of, for example, a fluorescent tube or a white light-emitting diode (LED).
- the auxiliary lamp driving circuit 604 puts on the auxiliary lamp 603 by outputting driving power to the auxiliary lamp 603 based on the control of the controller 4.
- the LCD driver circuit 601 is a circuit to display image data input from the IPP 306 on the LCD displaying unit 602.
- the controlling unit 9 is provided with the release switches 901 to give a photographing instruction, the mode input unit 902, a power switch, a LCD switch, an auxiliary lamp switch, buttons with which function selection and other various settings are externally carried out, and the like.
- the symbols illustrated on the mode input unit 902 in Fig. 1 the symbols of a microphone (on the left), a camera (at the center), and a video camera (on the right) represent an audio recording mode, still image recording, and moving image recording, respectively.
- the flash lamp circuit 5 generates flashlight by control of the controller 4.
- the battery A 701 and the battery B 702 are, for example, a nickel-hydrogen cell, a lithium ion battery, a nickel-cadmium (NiCd) battery, or an alkaline cell.
- a supply voltage of the AC adapter 703 may be supplied, and the supply voltage is supplied inside of the digital camera 1 via the DC-DC converter 7.
- the DC-DC converter 7 has a built-in switch circuit that turns on/off various power sources that output the supply voltage inside of the digital camera 1 by control of the controller 4.
- the controller 4 is composed of a CPU, a ROM, a random access memory (RAM), an A/D converter, a D/A converter, and the like.
- the CPU controls the whole apparatus of the digital camera 1 according to instructions from the controlling unit 9, or an external operation instruction by a remote control (not shown) or the like using the RAM as a work area according to a control program stored in the ROM.
- the A/D converter and the D/A converter are externally prepared, they are prepared as the A/D 402 and the D/A 403, respectively.
- the controller 4 controls photographing actions, autoexposure (AE) actions, auto white balance (AWB) adjustment actions, autofocus (AF) actions, display, and the like.
- the controller 4 takes in analog information using the built-in A/D converter as one of information input units for various controls. Taking in the analog information is carried out with the built-in A/D converter with comparison to the reference voltage.
- the D/A converter is used for analog outputs.
- control of the IPP 306 and the controller 4, and data swapping are carried out via the system bus 404.
- the controller 4 is provided with a recording mode in which image data obtained by photographing a subject is recorded in the PC card 312, a playback mode in which the image data recorded in the PC card 312 is played back to be displayed on the LCD displaying unit 602, a monitoring mode in which a monitoring image photographed is directly displayed on the LCD displaying unit 602, and the like.
- a fix mode and an outside light adaptive mode are provided as for the display mode at the time when an image is displayed on the LCD displaying unit 602 in the playback mode and the monitoring mode.
- the mode selection is carried out by the controlling unit 9.
- the timing generator (TG) 301 generates a variety of timing signals based on horizontal and vertical synchronizing signals input from the IPP 306.
- the audio amplifying unit 8 amplifies analog signals of the microphone 801, the loudspeaker 802, and the earphone 803 via the A/D 402 or D/A 403 of the controller 4.
- a beeper from an output (not shown) of the controller 4 may be used in place of the loudspeaker 802 as the audio output unit.
- the vibration motor 1002. is one unit of a warning unit. Control signals from the controller 4 allow the vibration motor driving apparatus 1001 to operate and the driver 1001 drives the vibration motor 1002, thereby giving warning with vibration.
- Fig. 2 is a flowchart of an operation of a motor at a time of activation according to an embodiment of the present invention.
- the controller turns on power (step S1) to turn on the controller switch (step S2). Then, the feedback resistance are shorted to set the output voltage high (step S3).
- An operation of the DC-DC converter IC is initiated (step S4), thereby initiating a motor operation (step S5).
- the short of the feedback resistance is cancelled and the voltage is lowered (step S7). Then, the motor operation is halted ("YES" at step S8, step S9).
- Fig. 3 a flowchart of an operation of the motor at a time of termination according to an embodiment of the present invention.
- the controller switch is turned on (step S12).
- the feedback resistance are shorted and the output voltage is set high (step S13).
- the DC-DC converter IC is allowed to operate (step S14) to initiate a motor operation (step S15).
- the short of the feedback resistance is cancelled to lower the voltage (step S17), and the controller halts the motor operation (“YES” at step S18, step S19).
- the power switch and the DC-DC converter are turned off (step S20). In this way, in the same manner as in a case at the time of activation shown in Fig. 2, the short of the feedback resistance is also turned on/off at the time of termination, thereby controlling the motor drive voltage.
- the conventional disadvantages can be solved by preventing power loss as much as possible by changing the output voltage of the power source directly by means of variably changing the feedback resistance of the power circuit.
- the output voltage of the power source is directly changed by the feedback resistance at the time of high-speed activation or low-speed activation, thereby reducing power loss.
- the output voltage of the power source is directly changed by the feedback resistance at the time of termination in the same manner as in the time of activation, thereby reducing power loss.
- power loss is further reduced by changing the output voltage at the time of both activation and termination.
- the power when the voltage is changed until the power is turned off, the power is turned off, thereby preventing such power-off from occurring by setting the resistance values of the feedback resistance.
- the voltage can be lowered within a short time even when the voltage is lowered due to excess load. Therefore, there is no power loss.
- the voltage change can be carried out within a short time by shorting both ends of the rectifier diode not only at the above time but also at the time when a load is not applied. Therefore, there is no power loss.
- the use of the power circuit to control the output voltage via the feedback resistance for the power source of the lens barrel motor having a large effect on the batteries due to its large power consumption makes it possible to activate the motor at a high speed as well as to reduce power loss.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Dc-Dc Converters (AREA)
- Lens Barrels (AREA)
- Studio Devices (AREA)
- Control Of Electric Motors In General (AREA)
Abstract
Description
- The present invention relates to energization of a motor, and more specifically, to a motor driving apparatus that controls a power source of a lens barrel motor of a digital camera, a digital camera, and a motor controlling method.
- Conventionally, a lens barrel in cameras, such as a digital camera, is collapsibly mounted on the cameras to put emphasis on portability. Furthermore, there is a method for high-speed activation.
In the method, a high voltage is applied at a time of activation of a motor. Generally, by changing voltage of a series regulator connected to a power source, supply voltage is directly used when a motor is driven at a high speed, and the voltage is lowered during the motor is driven at an ordinary speed to reduce an electric current for the motor. - As a conventional technology, there is a "motor driving apparatus" that prevents severe shock and pulling-out of synchronism, and uncomfortable vibration noise that occur during acceleration control used when the motor is to be started. Such a technology is disclosed in, for example, Japanese Patent Application Laid-Open Application No. 2002-78385. Moreover, there is a "motor drive controller" that converges vibration control after a motor startup within a short time, and performs phase control and vibration control more accurately after the convergence. Such a technology is disclosed in, for example, Japanese Patent Application Laid-Open Application No. 2003-189692.
- However, in the conventional technology, power cannot sufficiently be reduced because the supply voltage is partially consumed by a series regulator.
- In the technology disclosed in Japanese Patent Application Laid-Open Application No. 2002-78385, as to a method in which the action of the power source itself is changed at a time of activation, although an input filter circuit is changeable, change in voltage due to change of feedback resistance is not taken into consideration. In addition, a method in which vibration is suppressed by control with sine waves is proposed in the technology disclosed in Japanese Patent Application Laid-Open Application No. 2003-189692, however, change in voltage due to change of feedback resistance is not taken into consideration.
- It is an object of the present invention to solve at least the above problems in the conventional technology.
- A motor driving apparatus according to one aspect of the present invention includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor. The power circuit varies resistance of the feedback variable resistance at a time of start of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- A motor driving apparatus according to another aspect of the present invention includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor. The power circuit varies resistance of the feedback variable resistance at a time of termination of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- A motor driving apparatus according to still another aspect of the present invention includes a power circuit that controls, via a feedback variable resistance, an output voltage that is applied to a motor. The power circuit varies resistance of the feedback variable resistance at times of start and termination of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- A digital camera according to still another aspect of the present invention includes the motor driving apparatus according to the above aspects of the present invention.
- A motor controlling method according to still another aspect of the present invention includes controlling, via a feedback variable resistance, an output voltage that is applied to a motor. The controlling includes varying resistance of the feedback variable resistance at a time of at least one of start of activation of the motor thereby causing the motor to activate at any one of a high speed and a low speed.
- The other objects, features, and advantages of the present invention are specifically set forth in or will become apparent from the following detailed description of exemplary embodiments of the invention when read in conjunction with the accompanying drawings, in which:
- Fig. 1 is a block diagram of a digital camera according to an embodiment of the present invention;
- Fig. 2 is a flowchart of an operation of a motor at a time of activation according to an embodiment of the present invention;
- Fig. 3 is a flowchart of an operation of the motor at a time of termination according to an embodiment of the present invention;
- Fig. 4 is a block diagram of a battery terminal voltage measuring unit according to a first embodiment of the present invention; and
- Fig. 5 is a block diagram of a battery terminal voltage measuring unit according to a second embodiment of the present invention.
- Exemplary embodiments of a motor driving apparatus, a digital camera, and a motor controlling method according to the present invention are explained below in detail with reference to the accompanying drawings.
- Fig. 4 is a block diagram of a battery terminal voltage measuring unit according to a first embodiment of the present invention. As shown in Fig. 4, the battery terminal voltage measuring unit includes a
power source unit feedback resistance 2 1-17, a feedback resistance 3 1-18, a feedback resistance short transistor 1-19, and a direct circuit (DC)-DC converter integrated circuit (IC) 1-2. - The DC-DC converter IC 1-2 includes an IC power source 1-3, an output drive circuit 1 1-4, a pulse width modulation (PWM) comparator 1-8, a sawtooth wave generating circuit 1-7, an error amplifier (AMP) 1-9, an internal power source 1-10, and a short/overvoltage protection circuit 1-23.
- When a
system controller 4 turns on the power switch 1-22, power is supplied to the power source of the DC-DC converter IC 1-2, thereby activating the IC power source 1-3. Since the output is still 0 volt (V), the DC-DC converter IC starts operating. The voltage divided by resistances of the feedback resistance 1 1-16, thefeedback resistance 2 1-17, and the feedback resistance 3 1-18 is input to the error AMP 1-9, and the output is compared with a voltage of the internal power source 1-10, and when the voltage is low, a control signal for the operation is input to the PWM comparator 1-8. - This signal and sawtooth wave levels are compared with each other by the PWM comparator 1-8 and pulse outputs are output. To drive a metal oxide semiconductor (MOS) 1-20, the pulse outputs are output through the output drive circuit 1-4. The short/overvoltage protection circuit 1-23 turns off the DC-DC converter IC when an output voltage exceeds a certain range.
- An electric charge stored in the voltage step up coil 1-12 by switching # operation of the MOS 1-20 is rectified by the rectifier diode 1-13 and supplied to the load 1-21 smoothened by the output smoothing capacitor 1-15. When the voltage is compared with that of the internal power source 1-10 and exceeds it, the MOS 1-20 turns off by a reverse operation of the above operation.
- Fig. 5 is a block diagram of a battery terminal voltage measuring unit according to a second embodiment of the present invention in which synchronized rectification is added. The battery terminal voltage measuring unit according to the second embodiment includes the
power source unit feedback resistance 2 1-17, the feedback resistance 3 1-18, the feedback resistance short transistor 1-19, and the DC-DC converter IC 1-2. - The DC-DC converter IC 1-2 includes the IC power source 1-3, the output drive circuit 1 1-4, an inverting circuit 1-5, an
output drive circuit 2 1-6, the PWM comparator 1-8, the sawtooth wave generating circuit 1-7, the error AMP 1-9, the internal power source 1-10, and the short/overvoltage protection circuit 1-23. - When the
system controller 4 turns on the power switch 1-22, power is supplied to the power source of the DC-DC converter IC 1-2, thereby activating the IC power source 1-3. Since the output is still 0 V, the DC-DC converter IC starts operating. The voltage divided by resistances of the feedback resistance 1 1-16, thefeedback resistance 2 1-17, and the feedback resistance 3 1-18 is input to the error AMP 1-9, and the output is compared with a voltage of the internal power source 1-10, and when the voltage is low, a control signal for the operation is input to the PWM comparator 1-8. - This signal and sawtooth wave levels are compared with each other by the PWM comparator 1-8 and pulse outputs are output. To drive the metal oxide semiconductors (MOSs) 1-20 and 1-14, the pulse outputs are output through the output drive circuit 1-4, the inverting circuit 1-5, and the output drive circuit 1-6.
- An electric charge stored in the voltage step up coil 1-12 by switching # operation of the MOS 1-20 is rectified by the rectifier diode 1-13 and supplied to the load 1-21 smoothened by the output smoothing capacitor 1-15. The MOS 1-14 turns on while the diode carries out the rectifying action and is a switch for synchronized rectification that supplements Vf of the diode. Both metal oxide semiconductors (MOSs) 1-14 and 1-20 may be substituted with transistors. Further, the transistor may be substituted with the MOS.
- Fig. 1 is a block diagram of a digital camera according to an embodiment of the present invention. The digital camera includes a
lens system 2, afocus lens system 201, azoom lens system 202, amechanism 203 including diaphragm and the like, afocus motor 204, azoom motor 205, adiaphragm motor 206, a focusmotor driving apparatus 207, a zoommotor driving apparatus 208, a diaphragm motor driving apparatus 209 (ashutter motor 210 and a shuttermotor driving apparatus 211 are separately illustrated in this example), a timing generator (TG) 301, a charge coupled device (CCD) 302, a correlation double sampling (CDS)circuit 303, an automatic gain control amplifier (AGC amplifier) 304, an analog-to-digital (A/D)converter 305, an image pre-processor (IPP) 306, a discrete cosine transform (DCT) 308, a Huffman encoder/decoder 309, a memory card controller (MCC) 310, a read only memory (RAM) 307 (inner memory), acard interface 311, a personal computer (PC) card 312 (including memory card etc.), a controller (central processing unit (CPU)) 4, a flash memory (electrically erasable programmable read only memory (EEPROM)) 401, an A/D converter forcontroller 402, a digital-to analog (D/A) converter forcontroller 403, system bus lines 404, a liquid crystal display (LCD) displayingunit 602, anauxiliary lamp 603, an auxiliarylamp driving circuit 604, anLCD driver circuit 601, aflash lamp 5, a DC-DC converter 7, abattery A 701, abattery B 702, an alternating current (AC)adapter 703, a controllingunit 9,release switches 901, amode input unit 902, anaudio amplifying unit 8, amicrophone 801, aloudspeaker 802, anearphone 803, a vibrationmotor driving apparatus 1001, and avibration motor 1002. - The lens unit includes the
mechanism 203 including thelens system 2, a diaphragm, a filter, and the like. A mechanical shutter of themechanism 203 exposes two fields. Although, in Fig. 1, a shutter mechanism is separately illustrated as an exposing unit, themechanism 203 may also serve as the shutter mechanism. Thelens system 2 is formed of, for example, a varifocal lens and is constructed from thefocal lens system 201 and thezoom lens system 202. - The focus
motor driving apparatus 207 drives thefocus motor 204 according to control signals supplied by thecontroller 4 to move thefocal lens system 201 to the optical axis direction. The zoommotor driving apparatus 208 drives thezoom motor 205 according to the control signals supplied by thecontroller 4 to move thezoom lens system 202 to the optical axis direction. The diaphragmmotor driving apparatus 209 drives themechanism 203 according to the control signals supplied by thecontroller 4 to set, for example, a diaphragm stop of the diaphragm. - The
CCD 302 converts an image input via the lens unit into electric signals (analog image data). TheCDS circuit 303 is a circuit to make noise reduced for a CCD-type image pickup device. - Furthermore, the
AGC amplifier 304 corrects the level of the signals that have been subjected to correlation double sampling in theCDS circuit 303. The setting is done by setting the setting data (control voltage) on theAGC amplifier 304 via the D/A converter built in theAGC amplifier 304. Furthermore, the A/D converter 305 converts the analog image data input from the CCD via theAGC amplifier 304 into digital image data. In other words, the output signals from theCCD 302 are converted into digital signals via theCDS circuit 303 and theAGC amplifier 304, and by the A/D converter 305 at an optimum sampling frequency, for example, at integral multiple of sub-carrier frequencies of national television system committee (NTSC) signals). - The image pre-processor (IPP) 306, the discrete cosine transform (DCT) 308, and the Huffman encoder/
decoder 309 that serve as a digital signal processing unit separate the digital image data input from the A/D converter 305 into color difference (Cb and Cr) and luminance (Y), and carry out various processing and data processing to correct and compress/extend an image. TheDCT 308 and the Huffman encoder/decoder 309 carry out, for example, orthogonal transformation/reverse orthogonal transformation that is one step of image compression/extension compliant with the Joint Photographic Experts Group (JPEG), Huffman coding/decoding that is one step of the image compression/extension compliant with the JPEG, and so forth. - The
IPP 306 detects luminance data (Y) of image data G, and outputs an autoexposure (AE) evaluation value corresponding to the detected luminance data (Y) to thecontroller 4. This AE evaluation value represents luminance (brightness) of the subject. Further, theIPP 306 outputs auto white balance (AWB) evaluation values corresponding to each luminance data (Y) of red (R), green (G) and blue (B) image data, respectively, to thecontroller 4 within a preset color temperature range. These AWB evaluation values represent color elements of the subject. - Furthermore, the memory card controller (MCC) 310 stores the compression-processed image once and records it to the
PC card 312 or reads it out of thePC card 312 via thecard interface 311. - The numeral 313 represents a driver for external communication and is used for communication with external units according to standard communication protocols such as universal serial bus (USB) and Institute of Electrical and Electronics Engineers (IEEE) 1394, and connected to a personal computer (PC) 001 and the like, to swap data with them. Alternatively, the driver for
external communication 313 is made capable of connecting to thePC 001 or theAC adapter 703 via a communication/power source adapter connectable to a camera, thereby allowing power and communication to be swapped. - The
LCD displaying unit 602 is formed of a transmission-type LCD and displays image data, an operation menu, and the like. Theauxiliary lamp 603 is a back light to illuminate theLCD displaying unit 602 and is formed of, for example, a fluorescent tube or a white light-emitting diode (LED). The auxiliarylamp driving circuit 604 puts on theauxiliary lamp 603 by outputting driving power to theauxiliary lamp 603 based on the control of thecontroller 4. - The
LCD driver circuit 601 is a circuit to display image data input from theIPP 306 on theLCD displaying unit 602. The controllingunit 9 is provided with the release switches 901 to give a photographing instruction, themode input unit 902, a power switch, a LCD switch, an auxiliary lamp switch, buttons with which function selection and other various settings are externally carried out, and the like. As to the symbols illustrated on themode input unit 902 in Fig. 1, the symbols of a microphone (on the left), a camera (at the center), and a video camera (on the right) represent an audio recording mode, still image recording, and moving image recording, respectively. - The
flash lamp circuit 5 generates flashlight by control of thecontroller 4. Thebattery A 701 and thebattery B 702 are, for example, a nickel-hydrogen cell, a lithium ion battery, a nickel-cadmium (NiCd) battery, or an alkaline cell. In some cases, a supply voltage of theAC adapter 703 may be supplied, and the supply voltage is supplied inside of the digital camera 1 via the DC-DC converter 7. The DC-DC converter 7 has a built-in switch circuit that turns on/off various power sources that output the supply voltage inside of the digital camera 1 by control of thecontroller 4. - The
controller 4 is composed of a CPU, a ROM, a random access memory (RAM), an A/D converter, a D/A converter, and the like. The CPU controls the whole apparatus of the digital camera 1 according to instructions from the controllingunit 9, or an external operation instruction by a remote control (not shown) or the like using the RAM as a work area according to a control program stored in the ROM. When the A/D converter and the D/A converter are externally prepared, they are prepared as the A/D 402 and the D/A 403, respectively. Specifically, thecontroller 4 controls photographing actions, autoexposure (AE) actions, auto white balance (AWB) adjustment actions, autofocus (AF) actions, display, and the like. Thecontroller 4 takes in analog information using the built-in A/D converter as one of information input units for various controls. Taking in the analog information is carried out with the built-in A/D converter with comparison to the reference voltage. - On the other hand, the D/A converter is used for analog outputs. For example, control of the
IPP 306 and thecontroller 4, and data swapping are carried out via the system bus 404. Further, thecontroller 4 is provided with a recording mode in which image data obtained by photographing a subject is recorded in thePC card 312, a playback mode in which the image data recorded in thePC card 312 is played back to be displayed on theLCD displaying unit 602, a monitoring mode in which a monitoring image photographed is directly displayed on theLCD displaying unit 602, and the like. As for the display mode at the time when an image is displayed on theLCD displaying unit 602 in the playback mode and the monitoring mode, a fix mode and an outside light adaptive mode are provided. The mode selection is carried out by the controllingunit 9. - Various parameters and data of a digital camera are recorded in the
flash memory 401. The timing generator (TG) 301 generates a variety of timing signals based on horizontal and vertical synchronizing signals input from theIPP 306. - The
audio amplifying unit 8 amplifies analog signals of themicrophone 801, theloudspeaker 802, and theearphone 803 via the A/D 402 or D/A 403 of thecontroller 4. A beeper from an output (not shown) of thecontroller 4 may be used in place of theloudspeaker 802 as the audio output unit. - The vibration motor 1002.is one unit of a warning unit. Control signals from the
controller 4 allow the vibrationmotor driving apparatus 1001 to operate and thedriver 1001 drives thevibration motor 1002, thereby giving warning with vibration. - Fig. 2 is a flowchart of an operation of a motor at a time of activation according to an embodiment of the present invention. The controller turns on power (step S1) to turn on the controller switch (step S2). Then, the feedback resistance are shorted to set the output voltage high (step S3). An operation of the DC-DC converter IC is initiated (step S4), thereby initiating a motor operation (step S5). When switching of the supply voltage that allows the motor operation is necessary ("YES" at step S6), the short of the feedback resistance is cancelled and the voltage is lowered (step S7). Then, the motor operation is halted ("YES" at step S8, step S9).
- Fig. 3 a flowchart of an operation of the motor at a time of termination according to an embodiment of the present invention.
When the motor drive terminates ("YES" at step S11), the controller switch is turned on (step S12). Then, the feedback resistance are shorted and the output voltage is set high (step S13). The DC-DC converter IC is allowed to operate (step S14) to initiate a motor operation (step S15). When switching of the supply voltage that allows the motor operation is necessary ("YES" at step S16), the short of the feedback resistance is cancelled to lower the voltage (step S17), and the controller halts the motor operation ("YES" at step S18, step S19). Then, the power switch and the DC-DC converter are turned off (step S20). In this way, in the same manner as in a case at the time of activation shown in Fig. 2, the short of the feedback resistance is also turned on/off at the time of termination, thereby controlling the motor drive voltage. - According to the embodiments of the present invention, the conventional disadvantages can be solved by preventing power loss as much as possible by changing the output voltage of the power source directly by means of variably changing the feedback resistance of the power circuit.
- Therefore, according to the present embodiment, the output voltage of the power source is directly changed by the feedback resistance at the time of high-speed activation or low-speed activation, thereby reducing power loss.
- Furthermore, according to the present embodiment, the output voltage of the power source is directly changed by the feedback resistance at the time of termination in the same manner as in the time of activation, thereby reducing power loss. In addition, power loss is further reduced by changing the output voltage at the time of both activation and termination.
- Moreover, according to the present embodiment, when the voltage is changed until the power is turned off, the power is turned off, thereby preventing such power-off from occurring by setting the resistance values of the feedback resistance.
- Furthermore, according to the present embodiment, the voltage can be lowered within a short time even when the voltage is lowered due to excess load. Therefore, there is no power loss.
- Moreover, according to the present embodiment, when synchronized rectification is used together, the voltage change can be carried out within a short time by shorting both ends of the rectifier diode not only at the above time but also at the time when a load is not applied. Therefore, there is no power loss.
- Furthermore, according to the present embodiment, the use of the power circuit to control the output voltage via the feedback resistance for the power source of the lens barrel motor having a large effect on the batteries due to its large power consumption makes it possible to activate the motor at a high speed as well as to reduce power loss.
- While the embodiments of the present invention have been explained as above, the present invention is not limited to the above embodiments, and various modifications are possible without departing from the scope of the invention, as defined in the appended claims.
- According to the present invention, it is possible to reduce power loss.
- The present document incorporates by reference the entire contents of Japanese priority document, 2004-053694 filed in Japan on February 27, 2004.
Claims (11)
- A motor driving apparatus comprising a power circuit that controls, via a feedback variable resistance (1-16, 1-17, 1-18), an output voltage that is applied to a motor (204, 205, 206, 210), wherein
the power circuit varies the resistance of the feedback variable resistance (1-16, 1-17, 1-18) at the time of either or both of the start or termination of activation of the motor (204, 205, 206, 210) thereby causing the motor (204, 205, 206, 210) to activate at either one of a high speed and a low speed. - A motor driving apparatus according to claim 1, wherein the power circuit includes an overvoltage protection circuit (1-23), and a short protection circuit (1-23), and
the power circuit varies the resistance in such a manner that neither the output voltage is within a range such that of the overvoltage protection circuit (1-23) and the short protection circuit (1-23) is activated. - A motor driving apparatus according to any one of claims 1 or 2, wherein the power circuit varies the resistance in such a manner that the output voltage is reduced when a load is applied.
- A motor driving apparatus according to any one of claims 1 to 5, wherein the power circuit varies, by discharging a voltage of a capacitor (1-15) provided in a later stage, the resistance in such a manner that the output voltage is reduced.
- A motor driving apparatus according to any one of claims 1 to 3, wherein the motor driving apparatus is used for a power source of a motor (204, 205, 206, 210) that is used for a lens barrel (2) for an image input unit.
- A digital camera (1) comprising a motor driving apparatus according to any one of claims 1 to 5.
- A motor controlling method comprising controlling, via a feedback variable resistance (1-16, 1-17, 1-18), an output voltage that is applied to a motor (204, 205, 206, 210), wherein
the controlling includes varying the resistance of the feedback variable resistance (1-16, 1-17, 1-18) at a time of at least one of the start or termination of activation of the motor (204, 205, 206, 210) thereby causing the motor (204, 205, 206, 210) to activate at either one of a high speed and a low speed. - A motor controlling method according to claim 7, wherein the controlling includes varying the resistance in such a manner that the output voltage is within a range such that neither one of an overvoltage protection circuit (1-23) and a short protection circuit (1-23) that are included in a power circuit is activated.
- A motor driving apparatus according to claim 7 or 8, wherein the controlling includes varying the resistance in such a manner that the output voltage is reduced when a load is being applied.
- The motor controlling method according to any one of claims 7 to 9, wherein the controlling includes varying, by discharging a voltage of a capacitor (1-15) that is provided in a later stage in a power circuit, the resistance in such a manner that the output voltage is reduced.
- A motor controlling method according to any one of claims 7 to 10, wherein the motor controlling method is used to control a power source of a motor (204, 205, 206, 210) that is used for a lens barrel (2) for an image input unit (1).
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2004053694A JP4541723B2 (en) | 2004-02-27 | 2004-02-27 | Motor drive device, digital camera, and motor control method |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1617283A1 true EP1617283A1 (en) | 2006-01-18 |
EP1617283B1 EP1617283B1 (en) | 2009-05-27 |
Family
ID=34879712
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP05251119A Expired - Fee Related EP1617283B1 (en) | 2004-02-27 | 2005-02-25 | Motor driving apparatus, digital camera, and motor controlling method |
Country Status (5)
Country | Link |
---|---|
US (1) | US7133603B2 (en) |
EP (1) | EP1617283B1 (en) |
JP (1) | JP4541723B2 (en) |
CN (1) | CN1758529B (en) |
DE (1) | DE602005014586D1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2021081932A1 (en) * | 2019-10-31 | 2021-05-06 | Huawei Technologies Co., Ltd. | Driver circuit and method for controlling lens actuators |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006331144A (en) * | 2005-05-27 | 2006-12-07 | Toshiba Corp | Electronic equipment |
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US4246521A (en) * | 1978-04-28 | 1981-01-20 | Yamamoto Electric Industrial Co., Ltd. | DC Motor speed control system |
DE3123350A1 (en) * | 1981-06-12 | 1982-12-30 | Kautt & Bux Kg, 7000 Stuttgart | Device for influencing the current and rotation speed of a universal motor in accordance with the phase-gating process |
US4458992A (en) * | 1982-09-29 | 1984-07-10 | Preston Howard J | Automatic exposure correction system |
JPH10225160A (en) | 1998-03-20 | 1998-08-21 | Riken Corp | Dc motor drive circuit |
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US3697158A (en) * | 1970-09-28 | 1972-10-10 | Bell & Howell Co | Sound-on-film recording system |
DE2341164C3 (en) * | 1972-08-16 | 1978-07-13 | Canon K.K., Tokio | Electrical control device for a camera |
JPS5996865A (en) * | 1982-11-24 | 1984-06-04 | Matsushita Electric Ind Co Ltd | Power source |
JPS60149032A (en) * | 1984-01-13 | 1985-08-06 | Olympus Optical Co Ltd | Automatic control camera of stop-down value |
GB8516207D0 (en) * | 1985-06-26 | 1985-07-31 | Samuelson D W | Cinematograph camera flicker control device |
JPS62143929U (en) * | 1986-03-07 | 1987-09-10 | ||
JPS6339492A (en) | 1986-08-01 | 1988-02-19 | Ricoh Co Ltd | Motor control circuit |
JPS63114581A (en) | 1986-10-29 | 1988-05-19 | Ricoh Co Ltd | Motor controller |
JPS63114578A (en) | 1986-10-29 | 1988-05-19 | Ricoh Co Ltd | Motor speed control device |
DE3940408A1 (en) * | 1989-02-08 | 1991-06-13 | Arnold & Richter Kg | DEVICE FOR EXPOSURE CONTROL OF A RUNNING CAMERA |
US5051672A (en) * | 1989-04-28 | 1991-09-24 | Kabushiki Kaisha Riken | Automatic window/door system |
US5907725A (en) * | 1996-01-26 | 1999-05-25 | Asahi Kogaku Kogyo Kabushiki Kaisha | Electronically controlled camera |
JP4422875B2 (en) | 2000-08-30 | 2010-02-24 | キヤノン株式会社 | Motor drive device |
JP3802350B2 (en) * | 2001-01-15 | 2006-07-26 | 新キャタピラー三菱株式会社 | Can crusher |
JP2003289692A (en) | 2002-03-28 | 2003-10-10 | Tokico Ltd | Motor |
-
2004
- 2004-02-27 JP JP2004053694A patent/JP4541723B2/en not_active Expired - Fee Related
-
2005
- 2005-02-25 EP EP05251119A patent/EP1617283B1/en not_active Expired - Fee Related
- 2005-02-25 CN CN2005100716652A patent/CN1758529B/en not_active Expired - Fee Related
- 2005-02-25 US US11/065,575 patent/US7133603B2/en not_active Expired - Fee Related
- 2005-02-25 DE DE602005014586T patent/DE602005014586D1/en active Active
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US4246521A (en) * | 1978-04-28 | 1981-01-20 | Yamamoto Electric Industrial Co., Ltd. | DC Motor speed control system |
DE3123350A1 (en) * | 1981-06-12 | 1982-12-30 | Kautt & Bux Kg, 7000 Stuttgart | Device for influencing the current and rotation speed of a universal motor in accordance with the phase-gating process |
US4458992A (en) * | 1982-09-29 | 1984-07-10 | Preston Howard J | Automatic exposure correction system |
JPH10225160A (en) | 1998-03-20 | 1998-08-21 | Riken Corp | Dc motor drive circuit |
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WO2021081932A1 (en) * | 2019-10-31 | 2021-05-06 | Huawei Technologies Co., Ltd. | Driver circuit and method for controlling lens actuators |
Also Published As
Publication number | Publication date |
---|---|
EP1617283B1 (en) | 2009-05-27 |
US7133603B2 (en) | 2006-11-07 |
US20050191043A1 (en) | 2005-09-01 |
JP2005245158A (en) | 2005-09-08 |
JP4541723B2 (en) | 2010-09-08 |
CN1758529B (en) | 2010-06-16 |
DE602005014586D1 (en) | 2009-07-09 |
CN1758529A (en) | 2006-04-12 |
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